Method of preventing a dent from being damaged by a weft yarn during beating and the device for accomplishing the same

ABSTRACT

A method and device for undulating a fabric sheet near the fell front so as not to cause the weft yarn to come into contact with the same portion of a dent. The device comprises a cross bar positioned below and in contact with the fabric sheet transversely to the same near the fell front. Rotation of the cloth roller causes an undulating motion of the cross bar so that the fabric sheet is undulated near the fell front, whereby the points of contact between the weft yarn and the dent during beating differs from time to time. In another embodiment, the cross bar is drivably coupled with the shaft of a friction roller by means of an angled rod in such a manner that rotation of the friction roller causes an undulating motion of the cross bar.

United States Patent Uehara 51 Sept. 5, 1972 [54] METHOD OF PREVENTING ADENT FROM BEING DAMAGED BY A WEFT YARN DURING BEATING AND THE DEVICE FORACCOMPLISHING THE SAME [72] Inventor: Ya sunoriUehara, flolgyo, Japan[73] Assignee: Nissan Motor Company, Limited,

5/1971 Rambousek ..l39/29l R Primary Examiner-Henry S. JaudonAttomeyMcCarthy, Depaoli, OBrien & Price 7] ABSTRACT A method and devicefor undulating a fabric sheet near the fell front so as not to cause theweft yarn to come into contact with the same portion of a dent. Thedevice comprises a cross bar positioned below and in contact with thefabric sheet transversely to the same near the fell front. Rotation ofthe cloth roller causes an undulating motion of the cross bar so thatthe fabric sheet is undulated near the fell front, whereby the points ofcontact between the weft yarn and the dent during beating differs fromtime to time. In another embodiment, the cross bar is drivably coupledwith the shaft of a friction roller by means of an angled rod in such amanner that rotation of the friction roller causes an undulating motionof the cross bar.

4 Claims, 3 Drawing Figures PATENTEDSEP 5:912 3588.808

INVENTOR YAS tM/ gl (/E/l/IEH ATTORNEYS METHOD OF PREVENTING A DENT FROMBEING DAMAGED BY A WEFT YARN DURING BEATING AND THE DEVICE FORACCOMPLISI-IING THE SAME This invention relates to the beating of a weftyarn and more particularly to a method of preventing a dent from beingdamaged by the weft yarn during beating and the device for accomplishingthe same.

In a conventional loom, beating is effected by causing the reed to movea predetermined length of weft in its straightened state to the fellfront, with the length of weft kept in contact with substantially thesame portion of the dent of the reed. Thus, the dent tends to be damagedonly at that particular portion contacted by the weft yarn. In casewhere a hard thread such as one made of polyester fiber is used as aweft yarn, the dent becomes unusuable after as short as 1,000 to 2,000meters of cloth has been produced.

It is therefore an object of this invention to provide a new andimproved method of preventing a dent from being damaged by a weft yarnduring heating.

It is another object of this invention to provide a device foraccomplishing the above method.

It is a further object of this invention to provide a device in whichthe fabric sheet is undulated near the fell front so as not to cause aweft yarn to come into contact with the same portion of the dent.

In the drawings:

FIG. 1 is a schematic view of a loom incorporating the present device;

FIG. 2 is a detailed view of the present device as shown in FIG. 1; and

FIG. 3 is a fragmentary view showing another embodiment of thisinvention.

Referring now to FIG. 1, there is illustrated a loom incorporating thepresent device. The loom has a warp beam from which a warp array 11 isdrawn off to a heald 12 by way of a back rest roller 13. As is wellknown, the heald 12 serves to have upper and lower portions 14 and 15 ofthe parallel warp array 11 extending in their tensioned state so as toform a shed l6 therebetween. Provision of a shuttle or an injectionnozzle (not shown) is made for inserting a predetermined length of weft17 into the warp shed 16. The

loom also includes a reed 18 which is operated to beat the length ofweft 17 so as to produce a fabric sheet 19 immediately after the lengthof the weft 17 has been inserted into the warp shed 16. The fabric sheet19 thus woven is supplied through a friction roller 20 to a cloth roller21, where the sheet 19 is wound thereon.

According to the teachings of the invention, cam means 22 is providedwhose shaft 23 is drivably coupled with the shaft 24 of the cloth roller21 by means of a belt 25. Other coupling means such as a gearing may beused. Disposed above the cam 22 is a plunger 26 mounted in a stationarybracket 27 for reciprocating movement in the vertical direction. As isbest shown in FIG. 2, the plunger 26 has attached to the lower endthereof a cam follower 28 which is kept in rolling contact with the camsurface of the cam 22, so that the plunger 26 is moved up and down asthe cam 22 is rotated. Attached to the other end of the plunger 26 is across bar 29 which extends below and in contact with the fabric sheet 19transversely to the same over its entire breadth so as to support it ata location immediately adjacent the fell front30. Thus, rotation of thecam 22 causes an undulating motion of the fabric sheet 19 near the fellfront 30. While the cross bar is shown as supporting and undulating thefabric sheet, it is to be understood that the cross bar could bereplaced by a temple bar (not shown) which is directly coupled with theplunger.

In operation, the cloth roller 21 is rotated to wind the fabric product19 thereon and simultaneously to rotate the cam 22. Rotation of the cam22 causes the cam surface to be raised from the position represented bythe solid line 31 of FIG. 2 to that of the dotted line 32. As a result,the plunger 26 having the cross bar 29 attached to the top thereof ismoved upwards, lifting the fabric sheet 19 to the position representedby the dotted line 33. As the cam 22 is further rotated, on the otherhand, the plunger 26 is caused to move downwards by a downward forceexerted by the tensioned fabric sheet 19. Thus, the fabric sheet 19lowers itself together with the plunger 26 up to the position asrepresented by the solid line 34. In this way, rotation of the clothroller 21 results in undulation of the fabric sheet 19. Since the crossbar 29 is positioned below the fabric sheet 19 immediately adjacent thefell front 30, the fell front 30 is undulated, so that the points ofcontact between the weft yam l7 and the dent 35 of the reed 18 duringbeating differs from time to time. Therefore, there is littlepossibility of the dent 35 being damaged only at that particular portioncontacted by the weft yarn 17 during beating.

FIG. 3 is a fragmentary schematic view showing another embodiment ofthis invention which is different from that of FIG. 1 in that the crossbar is moved up and down by rotation of the friction roller 20. In thispreferred embodiment, the friction roller 20 has a cam 36 attached tothe shaft 37 thereof. The cam 36 has a cam surface with which a camfollower 38 is kept in rolling contact. The cam follower 38 is attachedto one end of an angled rod 39 pivotally mounted in a loom frame asshown at 40. The angled rod 39 has attached to the other end thereof across bar 41 which is positioned in a manner to extend below and incontact with the fabric sheet 19 transversely to the same immediatelyadjacent the fell front 30. In operation, rotation of the frictionroller 20 causes a pivotal movement of the angled rod 39, so that thefabric sheet 19 is undulated by the cross bar 41 attached to the angledrod 39.

In the embodiments as shown in FIGS. 1 and2, since a downward force isapplied to the cross bar by the tensioned fabric sheet, the verticalposition of the cross bar is related to the rotational angle of the cameven when the cross bar is being lowered. Therefore, by modifying theshape and size of the cam it is possible to control the verticaldisplacement of the cross bar. Although the cross bar as shown isundulated by rotation of the cloth roller or friction roller, it is tobe noted that other means for driving the cross bar for undulation canbe used. In this instance, it is desirable that the cross bar is drivenby such means as rotating at a relatively low speed, because the crossbar is undulated at a relatively long period.

What is claimed is:

1. A device for preventing a dent from being damaged by a weft yarn,comprising a cross bar positioned below and in contact with a fabricsheet transversely to the same and located immediately adjacent to thefell front, and means operatively connected to said cross bar forundulating the same together with the fabric sheet so as not to causethe weft yarn to come into contact with the same portion of the dent ateach beat-up, said means comprising a plunger mounted in a stationarybracket for reciprocating movement in the vertical direction and havingone end operatively connected to said cross bar, a cam follower attachedto the other end of said plunger, a cam having a cam surface with whichsaid cam follower is kept in rolling contact, and a driving means forcausing said cam to rotate, whereby the points of contact between thedent and the weft yarn during beating differs from time'to time.

2. A device according to claim 1, in which said driving means comprisesa belt for drivably coupling the shaft of a cloth roller with that ofsaid cam.

3. A device according to claim 1, in which said drivingmeans comprises abelt for drivably coupling the shaft of a friction roller with that ofsaid cam.

4. A device for preventing a dent from being damaged by a weft yarn,comprising a cross bar positioned below and in contact with a fabricsheet transversely to the same and located immediately adjacent to thefell front, and means operatively connected to said cross bar forundulating the same together with the fabric sheet so as not to causethe weft yarn to come into contact with the same portion of the dent ateach beat-up, said means comprising an angled rod pivotally mounted in aloom frame and having one end attached to said cross bar, a cam followerattached to the other end of said angled rod, and a cam mounted on theshaft of a friction roller for rotation therewith and having a camsurface with which said cam follower is kept in rolling contact, saidfriction roller engaging with said fabric sheet which is supplied to acloth roller and which is wound thereon and being slightly rotated whena beat up is completed by said dent, the cam surface of said cam being alocus of a point which moves as a distance between the point and theaxis of said cam is continuously slightly varied thereby slightlyundulating the fabric sheet when a beat up is completed by said dent,whereby the points of contact between the dent and the weft yarn duringheating differs from time to time.

1. A device for preventing a dent from being damaged by a weft yarn,comprising a cross bar positioned below and in contact with a fabricsheet transversely to the same and located immediately adjacent to thefell front, and means operatively connected to said cross bar forundulating the same together with the fabric sheet so As not to causethe weft yarn to come into contact with the same portion of the dent ateach beat-up, said means comprising a plunger mounted in a stationarybracket for reciprocating movement in the vertical direction and havingone end operatively connected to said cross bar, a cam follower attachedto the other end of said plunger, a cam having a cam surface with whichsaid cam follower is kept in rolling contact, and a driving means forcausing said cam to rotate, whereby the points of contact between thedent and the weft yarn during beating differs from time to time.
 2. Adevice according to claim 1, in which said driving means comprises abelt for drivably coupling the shaft of a cloth roller with that of saidcam.
 3. A device according to claim 1, in which said driving meanscomprises a belt for drivably coupling the shaft of a friction rollerwith that of said cam.
 4. A device for preventing a dent from beingdamaged by a weft yarn, comprising a cross bar positioned below and incontact with a fabric sheet transversely to the same and locatedimmediately adjacent to the fell front, and means operatively connectedto said cross bar for undulating the same together with the fabric sheetso as not to cause the weft yarn to come into contact with the sameportion of the dent at each beat-up, said means comprising an angled rodpivotally mounted in a loom frame and having one end attached to saidcross bar, a cam follower attached to the other end of said angled rod,and a cam mounted on the shaft of a friction roller for rotationtherewith and having a cam surface with which said cam follower is keptin rolling contact, said friction roller engaging with said fabric sheetwhich is supplied to a cloth roller and which is wound thereon and beingslightly rotated when a beat up is completed by said dent, the camsurface of said cam being a locus of a point which moves as a distancebetween the point and the axis of said cam is continuously slightlyvaried thereby slightly undulating the fabric sheet when a beat up iscompleted by said dent, whereby the points of contact between the dentand the weft yarn during beating differs from time to time.